Submission #393957

#	Time	Username	Problem	Language	Result	Execution time	Memory
393957		Return_0	Chase (CEOI17_chase)	C++17	100 / 100	283 ms	158980 KiB

chase

#pragma GCC optimize("Ofast,unroll-loops")
// #pragma comment(linker, "/stack:200000000")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,fma,tune=native")

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

typedef long long ll;
typedef long double ld;
typedef pair <ll, ll> pll;

#ifdef SINA
#define dbg(...) __f(#__VA_ARGS__, __VA_ARGS__)
template <typename Arg1> void __f(const char* name, Arg1&& arg1) { cout << name << " : " << arg1 << std::endl; }
template <typename Arg1, typename... Args> void __f (const char* names, Arg1&& arg1, Args&&... args) {
	const char* comma = strchr(names + 1, ',');cout.write(names, comma - names) << " : " << arg1<<" | ";__f(comma+1, args...); }
#define dbg2(x, j, n) cout<< #x << " : "; output((j), (n), x, 1); cout.flush();
#else
#define dbg(...) 0
#define dbg2(x, j, n) 0
#endif
#define SZ(x) ((ll)((x).size()))
#define File(s, t) freopen(s ".txt", "r", stdin); freopen(t ".txt", "w", stdout);
#define input(j, n, a) for (int _i = (j); _i < (n)+(j); _i++) cin>> a[_i];
#define output(j, n, a, t) for (int _i = (j); _i < (n)+(j); _i++) cout<< a[_i] << (((t) && _i != (n)+(j)-1)? ' ' : '\n');
#define kill(x) return cout<< (x) << endl, 0
#define cl const ll
#define fr first
#define sc second
#define lc (v << 1)
#define rc (lc | 1)
#define mid ((l + r) >> 1)
#define All(x) (x).begin(), (x).end()

cl inf = sizeof(ll) == 4 ? (1e9 + 10) : (3e18), mod = 1e9 + 7, MOD = 998244353;

template <class A,class B> ostream& operator << (ostream& out,const pair<A,B>&a){return out<<'('<<a.first<<", "<<a.second<<')';}
template <class A> ostream& operator << (ostream& out, const vector<A> &a) {
	out<< '['; for (int i = -1; ++i < int(a.size());) out<< a[i] << (i + 1 < int(a.size()) ? ", " : ""); return out<<']'; }
template <class T, typename _t = less <T> > using Tree = tree <T, null_type, _t, rb_tree_tag, tree_order_statistics_node_update>;

cl N = 1e5 + 3, K = 1e2 + 3;

ll val [N], dp1 [N][K], dp2 [N][K], ans;
int a [N], n, k;
vector <int> adj [N];

void dfs (const int &v = 1, const int pr = 0) {
	dp1[v][1] = val[v];
	for (auto &u : adj[v]) if (u != pr) {
		dfs(u, v);
		ll pd1, pd2;
		for (int i = 1; i < k; i++) {
			pd1 = max(dp1[u][i], dp1[u][i - 1] + val[v] - a[u]), pd2 = max(dp2[u][i], dp2[u][i - 1] + val[u] - a[v]);
			ans = max(ans, max(dp1[v][k - i] + pd2, dp2[v][k - i] + pd1));
			ans = max(ans, dp2[u][i] + val[v]);
		}
		for (int i = 1; i <= k; i++) {
			pd1 = max(dp1[u][i], dp1[u][i - 1] + val[v] - a[u]), pd2 = max(dp2[u][i], dp2[u][i - 1] + val[u] - a[v]);
			dp1[v][i] = max(dp1[v][i], pd1);
			dp2[v][i] = max(dp2[v][i], pd2);
			ans = max(ans, dp1[v][i]);
		}
	}
}

int main ()
{
	ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);

	cin>> n >> k;
	input(1, n, a);
	for (int i = 1, v, u; i < n; i++) {
		cin>> v >> u;
		adj[v].push_back(u);
		adj[u].push_back(v);
		val[v] += a[u];
		val[u] += a[v];
	}

	if (!k) kill(0);
	ans = *max_element(val, val + N);
	dfs();

	cout<< ans << endl;

	cerr<< "\nTime elapsed: " << 1000 * clock() / CLOCKS_PER_SEC << "ms\n";

	return 0;
}
/*
12 3
2 3 3 8 1 5 6 7 8 3 5 4
2 1
2 7
3 4
4 7
7 6
5 6
6 8
6 9
7 10
10 11
10 12

*/

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 30 / 30
• Subtask 4: 30 / 30